AT42QT1040-MMH Atmel, AT42QT1040-MMH Datasheet - Page 69

• Manufacturer Part Number: AT42QT1040-MMH
• Description: IC TOUCH SENSOR 4KEY 20-VQFN
• Manufacturer: Atmel
• Series: QTouch™r
• Type: Resistiver

Specifications of AT42QT1040-MMH

• Touch Panel Interface: 4, 2-Wire
• Number Of Inputs/keys: 4 Key
• Data Interface: I²C, Serial
• Data Rate/sampling Rate (sps, Bps): 200k
• Voltage Reference: Internal
• Voltage - Supply: 1.8 V ~ 5.5 V
• Current - Supply: 10mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-VQFN Exposed Pad, 20-HVQFN, 20-SQFN, 20-DHVQFN
• Output Type: Logic
• Input Type: Logic
• Supply Voltage: 1.8 V to 5.5 V
• Dimensions: 3 mm L x 3 mm W x 0.8 mm H
• Output Voltage: 0.7 V to 0.8 V
• Temperature Range: - 40 C to + 85 C
• Termination Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: AT42QT1040-MMH; AT42QT1040-MMHTR

Touch Sensors Design Guide
Planar Construction
Resolution
Self-capacitance Sensor
Sensor
Slider
Substrate
Touchscreen
Two-dimensional Sensor
Two Touch
Zero-dimensional Sensor
A method of construction in which the electrodes and the traces for the sensor are fabricated on the
same plane of the insulating substrate (for example, a PCB or Flex PCB). See
page
See also non-planar construction.
The measure of the smallest movement on a slider or touchscreen in an axis that causes a change in
the reported coordinate for that axis. Resolution is normally expressed in bits and tends to refer to
resolution across the whole axis in question. For example, a slider of length 100 mm and a resolution
of 10 bits could resolve a movement of 0.0977 mm. Jitter in the reported position degrades usable
resolution.
A sensor with only one direct connection to the sensor controller. A self-capacitance sensor tends to
emit electric fields in all directions. This type of sensor is suitable for implementating sensors for use
with QTouch
See also mutual-capacitance sensor.
The component that detects a touch. That is, a zero-dimensional key, a one-dimensional slider or
wheel, or a two-dimensional touchscreen or touchpad. Sensors consist of one or more electrodes.
A one-dimensional arrangement of electrodes whose capacitance changes when touched, allowing
the location of touch to be computed in one axis.
The base material carrying the electrodes. The substrate is usually a low-loss material, such as PCB
materials, acrylic, polycarbonate or glass, but it can be almost any insulating material.
A two-dimensional arrangement of electrodes whose capacitance changes when touched, allowing
the location of touch to be computed in both X and Y axes. The output from the XY computation is a
pair of numbers, typically 10-bits each, ranging from 0 to 1023, representing the extents of the
touchscreen active region.
A sensor that detects the movement of a finger during touch along two axes. Typical implementations
of two-dimensional sensors are touchscreens and touchpads.
The ability of a touchscreen to report two concurrent touches. The touches are reported as two separate
sets of XY coordinates.
A sensor that represents a single point of contact. The typical implementation of a zero-dimensional
sensor is a key.
3-1.
™
sensor controllers.
Glossary of Terms
Section 3.2 on
10620D–AT42–04/09
A-3